What D is BIM?

Building Information Modeling, or BIM, is typically defined as a way to represent and generate building data, often using 3D models. The Associated General Contractors, however, defines it as “an object-oriented building development tool that utilizes 5-D modeling concepts … .”

And Al Prowse, president of H. Griffiths Co. Ltd. Prowse who represents the Mechanical Contractors Association of Canada on the Canada BIM Council board, goes even further in this Daily Commercial News piece:

BIM has four key elements in terms of virtual construction, he says. These are: three-dimensional design; 4D scheduling capabilities; 5D cost estimating; and emergent 6D lifecycle management, which uses the model to perform activities related to post-construction management of a facility.

So, BIM is 6D, and I’m pretty sure we’re not talking about dimensions anymore. I say that because Wikipedia defines the fourth, fifth and sixth dimensions with lots of talk of math and science and fictional worlds. With BIM, 4D is basically time. And 5D is cost. And 6D is “lifecycle management.”

The Ds in BIM are largely theoretical at this point. Theoretically, you should be able add new “dimensions” of data to your models. This is theoretical because these new dimensions would require collaboration between project teams. Estimators for example, would have to trust the contractor’s model. This would require a lot of time working together and/or, in most cases, a real nice contingency plan. Another reason 4-6D is hard to achieve is that BIM models are often not interoperable with each other, even between Autodesk products.

At the end of the day, BIM is whatever D is most useful to the project and most efficient with your time. Usually, that’s simple 3D.